An ordinary syringe has no means for positively accurately and automatically dispensing repeated identical volumes of liquid. There are presently known special types of repeating dispensers designed for this purpose, such as the dispenser disclosed in U.S. Pat. No. 3,161,323 to J. H. Bent. Such a dispensing device employs a toothed ratchet bar which is drivingly connected to the dispensing plunger and which is moved incrementally through equal dispensing steps by a reciprocatory push button drivingly coupled to a pawl. In such a dispenser there is at present no practical way to change the volumetric dispensing rate except by changing the toothed ratched bar, namely, by substituting a new ratchet bar with a tooth pitch corresponding to the desired new repetitive dispensing rate. This requires the provision of a different ratchet bar for each particular dispensing rate. There is a definite need for a repeating dispensing syringe which can provide two or more repetitive dispensing rates with the same ratchet bar. Also, there is a need for an attachment for an ordinary syringe which can be employed for dispensing accurately identical volumes, and wherein two or more repetitive dispensing rates can be provided by the same attachment without requiring the use of different ratchet bars.